Adding termination power to the PowerBook HDI-30 adapter

eric

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Sep 2, 2021
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scsi.blue
I've been doing a lot of development on my PowerBook 170 - which also has a new battery from @jcs - and was getting annoyed at having to power my DB25 externally. Using a DB25 for development is just easier as I can reflash and grab the SD card quickly.

Which got me wondering why does the HDI-30 adapter on the PowerBook not pass through TERM POWER?

I toned out the HDI-30 to DB25 and sure enough the term power pin was connected.

Next I took apart the laptop and toned out, and the pin exists disconnected on the board.

IMG_4898.jpeg


So.. I took some bodge wire and connected it from the internal SCSI term power to the 5v line on the existing SCSI connector:
IMG_4899.jpeg
IMG_4902.jpeg


Result is a working HDI-30 powering a BlueSCSI v2!
IMG_4903.jpeg


Should add a diode in there to protect the PowerBook later, but it's working great now.

If you give it a try let me know if how it went for you. Also be sure to superglue back all the broken standoffs when you take the motherboard out :)